scholarly journals Gamma Radiation Aging Study of a Dow Corning SE 1700 Porous Structure Made by Direct Ink Writing

2015 ◽  
Author(s):  
Ward Small ◽  
Cindy T. Alviso ◽  
Tom R. Metz
Keyword(s):  
Gamma Radiation ◽  
Porous Structure ◽  
Direct Ink Writing ◽  
Aging Study

scholarly journals Thermal Aging Study of a Dow Corning SE 1700 Porous Structure Made by Direct Ink Writing: 1-Year Results and Long-Term Predictions

2015 ◽  
Author(s):  
Ward Small ◽  
Mark A. Pearson ◽  
Amitesh Maiti ◽  
Thomas R. Metz ◽  
Eric B. Duoss ◽  
...  
Keyword(s):  
Porous Structure ◽  
Thermal Aging ◽  
Direct Ink Writing ◽  
Aging Study

Effects of sterilization modes on the mechanical strengths of plaster of paris implants

1989 ◽  
Vol 47 ◽  
pp. 890-891
Author(s):  
K. Cowden ◽  
B. Giammara ◽  
T. Devine ◽  
J. Hanker
Keyword(s):  
Gamma Radiation ◽  
Calcium Sulfate ◽  
Significant Loss ◽  
Potassium Sulfate ◽  
Limiting Factors ◽  
Radiation Sterilization ◽  
Plaster Of Paris ◽  
Hardness Tester ◽  
Dry Heat ◽  
Calcium Sulfate Hemihydrate

Plaster of Paris (calcium sulfate hemihydrate, CaSO4. ½ H2O) has been used as a biomedical implant material since 1892. One of the primary limiting factors of these implants is their mechanical properties. These materials have low compressive and tensile strengths when compared to normal bone. These are important limiting factors where large biomechanical forces exist. Previous work has suggested that sterilization techniques could affect the implant’s strength. A study of plaster of Paris implant mechanical and physical properties to find optimum sterilization techniques therefore, could lead to a significant increase in their application and promise for future use as hard tissue prosthetic materials.USG Medical Grade Calcium Sulfate Hemihydrate Types A, A-1 and B, were sterilized by dry heat and by gamma radiation. Types A and B were additionally sterilized with and without the setting agent potassium sulfate (K2SO4). The plaster mixtures were then moistened with a minimum amount of water and formed into disks (.339 in. diameter x .053 in. deep) in polyethylene molds with a microspatula. After drying, the disks were fractured with a Stokes Hardness Tester. The compressive strengths of the disks were obtained directly from the hardness tester. Values for the maximum tensile strengths σo were then calculated: where (P = applied compression, D = disk diameter, and t = disk thickness). Plaster disks (types A and B) that contained no setting agent showed a significant loss in strength with either dry heat or gamma radiation sterilization. Those that contained potassium sulfate (K2SO4) did not show a significant loss in strength with either sterilization technique. In all comparisons (with and without K2SO4 and with either dry heat or gamma radiation sterilization) the type B plaster had higher compressive and tensile strengths than that of the type A plaster. The type A-1 plaster however, which is specially modified for accelerated setting, was comparable to that of type B with K2SO4 in both compressive and tensile strength (Table 1).

1073: What are Normal Reference Ranges for Testosterone in Older Men? Results from the Massachusetts Male Aging Study

2005 ◽  
Vol 173 (4S) ◽  
pp. 291-291
Author(s):  
Beth A. Mohr ◽  
Amy B. O'Donnell ◽  
Andre Guay ◽  
John B. McKinlay
Keyword(s):  
Older Men ◽  
Reference Ranges ◽  
Normal Reference ◽  
Aging Study

1236: Does Erectile Dysfunction Predict Risk of Metabolic Syndrome in Aging Men? Results from the Massachusetts Male Aging Study

2005 ◽  
Vol 173 (4S) ◽  
pp. 335-335 ◽  
Author(s):  
Ridwan Shabsigh ◽  
Andre B. Araujo ◽  
Amy B. O'Donnell ◽  
John B. McKinlay
Keyword(s):  
Metabolic Syndrome ◽  
Erectile Dysfunction ◽  
Aging Men ◽  
Aging Study

Risk and Resilience From Early Experiences to Longevity: Findings From the VA Normative Aging Study

2018 ◽  
Author(s):  
Lewina O. Lee ◽  
Carolyn M. Aldwin ◽  
Laura D. Kubzansky ◽  
Daniel K. Mroczek ◽  
Avron Spiro Iii
Keyword(s):  
Risk And Resilience ◽  
Early Experiences ◽  
Normative Aging Study ◽  
Aging Study ◽  
Normative Aging
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